How do I copy transform of a bone to an object?
Use constraints

How do you use constraints with Armatures?



In 2.8 can add a constraint, tweak the settings to suit, then hit the Disable and Keep Transform button to RHS of influence slider.

Remove constraint and it still has the transform.

As a script, in pose mode, Suzanne has default XYZ Euler rotation mode

&gt;&gt;&gt; monkey = C.scene.objects['Suzanne']
&gt;&gt;&gt; C.active_pose_bone
bpy.data.objects['Armature'].pose.bones["Bone"]

&gt;&gt;&gt; M = C.object.matrix_world @ C.active_pose_bone.matrix
&gt;&gt;&gt; monkey.rotation_euler = M.to_euler()